Low cost, high resolution optical beam-steering has potential applications such as use in Light Detection and Ranging (LIDAR), self-driving vehicles, pattern recognition, face-scanning, surveying, object scanning in manufacturing, object recognition in manufacturing, and optical communication switching equipment. LIDAR devices with few to no moving parts can be advantageous due to their operational reliability. In many applications, LIDAR is required to scan a wide target region, by directing different light beams in different directions, and detecting reflections from objects in corresponding different parts of the target region. This scanning may be termed optical scanning or optical beam-steering. Controllably directing one or multiple beams in these different directions adds to cost and complexity of the LIDAR. High-resolution LIDAR requires a larger number of beam directions per unit field of view.
Optical switches are used extensively in optical networks to controllably route received optical communication signals at switch input ports to desired output ports. The switch is set, for example via electronic control signals, so that an optical path is established from a selected input port to a selected output port. Some versions of these switches utilize a network of 1×2 or 2×2 switching cells, each of which operates based on Mach-Zehnder interferometers.
U.S. Patent Application Publication No. 2017/0371227 discloses an optical beamsteering device for LIDAR that uses a switch matrix to route input light to a single output coupler, such as a grating or photonic crystal. An aplanatic lens is interposed between the switch matrix and the output coupler. However, the incorporation of a lens and the use of a single output coupler may present design or an operational drawback in some applications and in particular limits the scalability and resolutions of such technique in high resolution applications.
Therefore there is a need for a LIDAR scanner and corresponding method that obviates or mitigates one or more limitations of the prior art.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.